Design And Functional Characteristics Of Micro-Nano-Anti-Reflection Optical Devices

Micro-nano optical is an optical branch which use micro-structural materials(or structural materials)to develop optical components.The anti-reflection of the optical components has been dependent on the multilayer structure for years.However,the laser damage threshold(LIDT)of the multilayer structure is too low,to seriously hampers the application and development of high power lasers.By preparing a specific microstructure on the substrate,a micro-nano-enhanced optics with higher transmittance and higher laser damage thresholds than the multilayer structure can be obtained,which can be effectively used for high-energy laser systems.We designed and fabricated two-dimensional cylindrical subwavelength gratings(SWGs)on fused silica for use in 1064 nm laser system.The transmittance and laser-induced damage threshold(LIDT)under the irradiation of 1064 nm pulses were performed,and a lower LIDT compared to blank fused silica was obtained.To understand damage mechanism quantitatively,macro-temperature on the SWGs integrated fused silica and micro-Electric field,micro-thermal-stress distribution on SWGs during the laser irradiation process were investigated by Finite Element Analysis,and the comparison between theoretical and experimental research indicated the presence of absorption centers and the non-uniform thermal mechanical distribution of SWGs contributed to the LIDT reduction on SWGs integrated fused silica.